In recent years, with the development of medical technology, medical imaging diagnosis apparatuses, in each of which an X-ray CT apparatus and a nuclear medicine diagnosis apparatus are combined, have been quickly gaining in popularity, as exemplified by a PET-CT apparatus in which an X-ray CT (Computed Tomography) apparatus and a PET (Positron Emission Tomography) are combined, and a SPECT-CT apparatus in which an X-ray CT apparatus and a SPECT (Single-Photon Emission Computed Tomography) apparatus are combined. In such a medical imaging diagnosis apparatus, the CT apparatus generates a morphological image which reflects an anatomical position of a photographed region. On the other hand, the nuclear medicine diagnosis apparatus generates a functional image which reflects intravital biochemical and physiological functions and metabolic information. The medical imaging diagnosis apparatus, in which the X-ray CT apparatus and nuclear medicine diagnosis apparatus are combined, generates a fusion image in which the morphological image and functional image are fused. The morphological image and functional image have a complementary relationship. Thus, the fusion image serves as an image for diagnosis of a patient with higher precision.
In order to generate a high-precision fusion image, measurements by the X-ray CT apparatus and nuclear medicine diagnosis apparatus need to be performed with high precision. For example, in the nuclear medicine diagnosis apparatus, a calibration work of a gamma ray detector needs to be exactly performed. In order to exactly perform the calibration work, it is necessary to exactly set a phantom, which is used for calibration, at the center position of the effective view field of the nuclear medicine diagnosis apparatus.
However, conventionally, setting of a phantom on a top-plate is manually performed by an operator, with a projector being used as a guide. Consequently, there is a case in which the phantom is not set at the center position of the actual effective view field, and there is a case in which the calibration work cannot exactly be carried out. In addition, in the case of actually imaging a subject by the nuclear medicine diagnosis apparatus, the setting of the subject is adjusted by, for example, a top-plate operation by the operator, with a projector being used as a guide. Thus, there is a case in which the subject is not set at the center position of the actual effective view field, and there is a possibility that measurement cannot exactly be performed.